The difference between an apartment and the street for a homeless veteran can often come down to a few hundred bucks for the rent deposit, according to the Veterans Matter advocacy group, which writes a check when the system falls short.

Ken Leslie, who has been running Veterans Matter since 2012, said he has a deal with the Department of Veterans Affairs -- "just let me know and I'll send a check to the landlord."

In a phone interview, he pointed to a recent case referred by the VA of a 67-year-old homeless veteran in Birmingham, Alabama, who was just $150 short of his deposit.

"That was the only thing keeping him out of a home. We sent a check the same day, and the guy was housed within minutes," said Leslie, who has personal experience with the homelessness issue. He is a former stand-up comedian, TV producer and head of a successful executive headhunter firm, but he was once homeless himself and living out of his car due to drug and alcohol addiction.

Leslie said the usual shortfall for rent deposits can range from about $600 to $1,800, depending on the area of the country, but the national average is about $750.

At Veterans Matter, he has recruited an A-list of celebrities for public service announcements and fund raising, including Willie Nelson, Katy Perry, Gary Sinise, Susan Sarandon, Kid Rock, Stevie Nicks, John Mellencamp, and Dusty Hill of ZZ Top, among others. They deliver the message that veterans "fought for us, now we fight for them."

In one of the promos, Dusty Hill said he heard about Veterans Matter while performing in Toledo, Ohio, and went over to check it out. "Once I looked at the program and saw that it was all direct help, I was all in on that," he said.

In coordination with the VA and the Department of Housing and Urban Development, Veterans Matter, now operating in 20 states, has helped get housing for more than 2,500 veterans, and the goal is to have 1,000 more in homes before the end of the year, Leslie said.

The group works with referrals from the VA for the Department of Housing and Urban Development-Veterans Affairs Supportive Housing Program, or HUD-VASH, which provides vouchers for rental assistance from HUD and case management from the VA.

When there is a problem with a rent deposit, Leslie said he hears from the licensed clinical social workers at the VA who work with homeless veterans and starts writing a check.

"Literally, they can request it on a phone deposit. We send the check the same day. It really is that simple," he said.

The HUD-VASH program derived from the commitment by then-VA Secretary Eric Shinseki and President Barack Obama in 2009 to end veteran homelessness by 2016.

The program has drastically reduced the number of homeless veterans from more than 140,000 in 2009, but the VA estimates that there are still about 38,000 veterans without a permanent place to live.

On Oct. 3, VA Secretary Robert Wilkie and HUD Secretary Ben Carson announced another $35 million in grants for the HUD-VASH program to combat veteran homelessness.

"We have few responsibilities greater than making sure those who have sacrificed so much in service to their country have a home they can call their own," Carson said.

Earlier, at a Sept. 26 hearing of the Senate Veterans Affairs Committee, Wilkie said the VA needs more licensed clinical social workers to manage cases for homeless veterans.

"The case managers are part of a larger issue we have in retaining those individuals, particularly in the social work field," he said.

One of the VA social workers coordinating with Leslie at Veterans Matter on rent deposits is Shane Dowling, a licensed clinical social worker at the VA's Ann Arbor, Michigan, health care system.

In one of Leslie's promos, Dowling said it used to take about 137 days to get a homeless veteran a lease under the HUD-VASH program in her area. "With the help of Veterans Matter, we've reduced that down to 71 days, which is absolutely amazing," she said.